4 .TH MH-ALIAS %manext5% "%nmhdate%" MH.6.8 [%nmhversion%]
6 mh-alias \- alias file for nmh message system
14 personal alias files and
15 the global alias file for
17 mail delivery, the file
25 describe aliases files used by the message transport system.
26 Each line of the alias file has the format:
58 .IR address\-group " := " address\-list
60 .RI " | = " UNIX\-group
61 .RI " | + " UNIX\-group
64 .IR address\-list " := " address
65 .RI " | " address\-list ", " address
69 Continuation lines in alias files end with `\\' followed by the newline
70 character. This applies to comment lines. Thus, a line following a
71 comment line that ends with a `\\' will be treated as a continuation of
74 .RI \*(lq Alias\-file \*(rq
79 is a group name (or number) from
81 An address is a \*(lqsimple\*(rq
82 Internet\-style address. Througout this file, case is ignored, except
85 If the line starts with a `<', then the file named after the `<' is
86 read for more alias definitions. The reading is done recursively, so a
87 `<' may occur in the beginning of an alias file with the expected results.
91 starts with a `<', then the file named after the
92 `<' is read and its contents are added to the
98 starts with an `=', then the file
100 is consulted for the UNIX\-group named after the `='. Each login name
101 occurring as a member of the group is added to the
107 starts with a `+', then the file
109 is consulted to determine the group\-id of the
110 UNIX\-group named after the `+'. Each login name occurring in the
112 file whose group\-id is indicated by this group is
119 is simply `*', then the file
121 is consulted and all login names with a userid
122 greater than some magic number (usually 200) are added to the
126 In match, a trailing \*(lq*\*(rq on an alias will match just about anything
127 appropriate. (See example below.)
129 An approximation of the way aliases are resolved at posting time is
130 (it's not really done this way):
134 Build a list of all addresses from the message to be delivered,
135 eliminating duplicate addresses.
138 If this draft originated on the local host, then for those addresses in
139 the message that have no host specified, perform alias resolution.
142 For each line in the alias file, compare \*(lqalias\*(rq against all of
143 the existing addresses. If a match, remove the matched \*(lqalias\*(rq
144 from the address list, and add each new address in the address\-group to
145 the address list if it is not already on the list. The alias itself is
146 not usually output, rather the address\-group that the alias maps to is
147 output instead. If \*(lqalias\*(rq is terminated with a `;' instead of
148 a `:', then both the \*(lqalias\*(rq and the address are output in the
149 correct format. (This makes replies possible since
152 and personal aliases are unknown to the mail transport system.)
155 Since the alias file is read line by line, forward references work, but
156 backward references are not recognized, thus, there is no recursion.
162 <%etcdir%/BBoardAliases
163 sgroup: fred, fear, freida
164 b-people: Blind List: bill, betty;
166 UNIX\-committee: <unix.aliases
174 The first line says that more aliases should immediately be read from
176 .IR %etcdir%/BBoardAliases .
177 Following this, \*(lqfred\*(rq
178 is defined as an alias for \*(lqfrated@UCI\*(rq, and \*(lqsgroup\*(rq
179 is defined as an alias for the three names \*(lqfrated@UCI\*(rq,
180 \*(rqfear\*(rq, and \*(rqfreida\*(rq.
182 The alias \*(lqb-people\*(rq is a blind list which includes the addresses
183 \*(lqbill\*(rq and \*(lqbetty\*(rq; the message will be delivered to those
184 addresses, but the message header will show only \*(lqBlind List: ;\*(rq
187 Next, the definition of \*(lqUNIX\-committee\*(rq is given by
193 \*(lqstaff\*(rq is defined as all users who are listed as members of the
194 group \*(lqstaff\*(rq in the
196 file, and \*(lqwheels\*(rq
197 is defined as all users whose group\-id in
199 is equivalent to the \*(lqwheel\*(rq group.
201 Finally, \*(lqeveryone\*(rq is defined as all users with a user\-id
204 greater than 200, and all aliases of the form
205 \*(lqnews.<anything>\*(rq are defined to be \*(lqnews\*(rq.
207 The key thing to understand about aliasing in
211 alias files are expanded into the headers of messages posted.
212 This aliasing occurs first, at posting time, without the knowledge of the
213 message transport system. In contrast, once the message transport system
214 is given a message to deliver to a list of addresses, for each address
215 that appears to be local, a system\-wide alias file is consulted. These
218 expanded into the headers of messages delivered.
223 quickly, do the following:
228 .IR \&.mh\(ruprofile ,
229 choose a name for your alias file, say
230 .RI \*(lq aliases \*(rq,
236 .\" ali: \-alias aliases
237 .\" send: \-alias aliases
238 .\" whom: \-alias aliases
244 .RI \*(lq aliases \*(rq
250 Start adding aliases to your
251 .RI \*(lq aliases \*(rq
258 .ta \w'%etcdir%/ExtraBigFileName 'u
259 ^%etcdir%/MailAliases~^global nmh alias file
262 .SH "PROFILE COMPONENTS"
266 .ta \w'ExtraBigProfileName 'u
267 ^Aliasfile:~^For a default alias file
271 ali(1), send(1), whom(1), group(5), passwd(5), conflict(8), post(8)
277 Although the forward-referencing semantics of
279 files prevent recursion, the
280 .RI \*(lq< " alias\-file" \*(rq
281 command may defeat this.
282 Since the number of file descriptors is finite (and very limited), such
283 infinite recursion will terminate with a meaningless diagnostic when
284 all the fds are used up.
286 Forward references do not work correctly inside blind lists.